The philosophy and opinions of the author cannot be construed asreflecting official US Army Medical Department policy.

Osteochondral fractures of the talus are a possibleconcomitant injury associated with ankle sprains. Theliterature reports an approximately 6-7% incidence (1, 2).They were first described by Berndt and Harty in 1959 (3).They presented a four-stage classification system (Figure 1).Stage I was an impaction injury. Normally, it is not seen onradiographs; however, it can be seen arthroscopically ordirectly through an arthrotomy. It can be represented as abone bruise onmagnetic resonance imaging (MRI). Stage IIis an incomplete fracture and difficult to identify on aradiograph. Stage III is a complete fracture withoutdisplacement. Stage IV is a complete fracture that isdisplaced. It can be displaced but still remain in its creator orit can be fully displaced lying outside the defect. It can evenbe rotated 180 degrees with the articular surface restinginferiorly. Berndt andHarty also described the mechanism ofinjury, morphology and the treatment options for thesefractures. The osteochondral fractures were reported aseither lateral or medial in their location on the talar dome.Osteochondral fractures of the talus can also be created byankle fracture mechanisms.

The lateral talar dome osteochondral fracture wasdescribed as shallow or wafer-shaped. They are located onthe anterior 1/4 or 1/3 portion of the talar dome. Thisanterior location makes them easily accessible for surgicalintervention either arthroscopically or through anarthrotomy. They are trauma related. The mechanism ofinjury was identified as a foot that was inverted with theankle dorsiflexed. There was a concurrent grade III injuryto the lateral collateral ligaments in stage III and IV (3, 4).The medial talar dome lesion was described as deeper,cup-shaped and located on the posterior 1/3 of thetalar dome. This location makes surgical access moreproblematic. They may be either acute or more commonlyof a chronic origin. The mechanism of injury is a footthat was plantarflexed and inverted while the tibia externallyrotates (2).

Berndt andHarty recommended nonsurgical treatmentfor lateral talar dome fractures in stages I and II and inmedial talar dome fractures stages I, II, and III. The reasonfor nonsurgical treatment of medial talar dome fracture stage

III was the difficulty in access. Surgical management wasrecommended for lateral talar dome fractures stages IIIand IV and for medial talar dome fractures stage IV. Thereason for surgical treatment in stage III lateral talar domefracture was instability of the fragment and a tendency notto consolidate.

The injury will present as a typical ankle sprain. Therewill be varying degrees of edema, ecchymosis, and paindepending on many factors, including the severity of theinjury, time from injury to examination, and individualpatient variables. There will be limited range of motion ofthe ankle and foot. There may be an anterior draweralthough it may be difficult to ascertain based on the amountof edema, pain, and the presence of muscular guarding.Circulatory and sensory function is usually normal. Routineankle radiographs generally demonstrate a stage III or IVosteochondral fracture. However, Brendt and Hartyreported a 57% misdiagnosis in their study (3). Additionalradiograph workup may include a computed tomography(CT) scan or MRI. The CT scan usually produces the bestosseous definition of the injury and is the most cost-effective.It is best to remember that both the radiographs and CT

ACUTE OSTEOCHONDRAL FRACTURES OF THE TALUS

George S. Gumann, DPM

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Figure 1. Berndt and Harty classification of osteo-chondral fractures of the talus.

scan reveal only the osseous component of the fracture andthe articular segment can be larger.

Nonoperative treatment has traditionally been castimmobilization with non-weightbearing for approximately6-8 weeks (1, 3, 5). If surgical intervention is indicated, thelateral talar dome osteochondral fracture is the easiest toapproach. Since it is located more anteriorly on the talardome, it can be well visualized with either an arthrotomy orarthroscopic approach. It is more commonly approachedwith arthrotomy. During the dissection, the rupturedfibular collateral ligaments are exposed and the ankle jointrevealed. The osteochondral fracture is evaluated and eitherexcised followed by micro-fracture or undergoes openreduction internal fixation (ORIF). The decision is based onthe condition of the osteochondral fracture and whetherORIF will produce a congruous articular surface. It is morecommon to excise the fragment than performORIF (Figure2). This is because the osteochondral fracture many times iscomminuted and plastically deformed. The defect is then

micro-fractured. This allows bleeding into the defect to forma clot that eventually forms fibrocartilage.

If ORIF is feasible, internal fixation can be achieved witheither metallic or absorbable lag screws (Figures 3 and 4).Care must be taken since the osseous portion of thefragment is thin, not to comminute it and to make sure thescrew is counter-sunk below the articular surface. Intra-operative radiographs are sometimes difficult to evaluateregarding screw position especially on the lateral projection.If the projection is not a true lateral, it can appear that thescrew is actually protruding into the joint. The lateralcollateral ligaments are primarily repaired. Postoperativemanagement is a short-leg cast for approximately 6 weekswith an initial period of non-weightbearing. An alternativeplan is to excise the lateral talar dome fracture arthro-scopically and treat the ligamentous injury nonoperativelywith cast immobilization. Arthroscopic excision may beproblematic because significant edema can obsure landmarksof the ankle, the hemarthrosis may obscure the fragment,

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Figure 2A. Stress radiograph of an acute ankle injury demonstrating agrade III ankle sprain with positive anterior drawer and talar tilt alongwith a lateral talar dome osteochondral stage IV fracture.

Figure 2C. Excision of the osteochondral fracture.

Figure 2B. Stress radiograph.

Figure 2D. Microfracture of the defect.

and the capsule-ligamentous disruption may result in fluidextravasation preventing joint distention.

The medial talar dome osteochondral fracture creates amore problematic surgical approach because of its moreposterior location on the medial talar dome. There are threepossible options: anteromedial (either arthrotomy orarthroscopic) approach, posteromedial (arthrotomy)approach, and medial malleolar osteotomy. Although acutemedial talar dome fractures are possible, reflecting upon 34.5years in practice, I believe them to be quite rare whenassociated with the ankle spraining mechanism as described

by Berndt and Hardy. Most that I have seen have beenlesions of a chronic nature. In fact, I have observed mostacute medial talar dome lesions occur with ankle fracturesand are located on the more anterior portion of the medialtalar dome. The previously-mentioned surgical approachesare equally applicable in either acute or chronic lesions. Auseful way to decide upon the appropriate surgical approachis to evaluate the lateral radiograph and attempt to decidehow large the fracture fragment is and the relative anterioror posterior location. Sometimes a forced dorsiflexion orplantarflexion lateral radiograph is helpful. However,

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Figure 3A. Mortise view of an acute lateral talardome osteochondral fracture.

Figure 3C. Computed tomography scan demonstrat-ing displacement and comminution of the fragment.

Figure 3B. Lateral view.

Figure 3D. Computed tomography scan.

attempting to manipulate the ankle in an acute injury maynot be feasible and this may need to be done once the patientis under anesthesia. If the fragment comes even with orslightly behind the anterior tibial lip, it can be reached froman anteromedial arthrotomy.

Additional exposure can be accomplished by performinga notch-plasty or grooving procedure at the medial bendof the tibia (Figure 5). This can also be done arthroscopi-cally. This will allow for more posterior visualization andspace for instrumentation to remove the fragment. The use

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Figure 3E. Fracture site.

Figure 3G. The fracture anatomically reduced.

Figure 3F. Fragment is reduced, provisionally stabilized, and fixatedwith a mini-fragment cortical screw.

Figure 3H. Intra-operative radiograph demonstrat-ing fracture reduction and good position of the screw.

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Figure 4A. Mortise view of an acute stage IV lateraltalar dome fracture.

Figure 4B. Lateral view.

Figure 4C. Computed tomography scan revealsthe fracture.

Figure 4D. Computed tomography reveals thefracture. Note that the fragment is upside down.The curved dorsal surface is facing inferiorly intothe defect.

of a noninvasive distractor can also increase access. If thefragment is more posteriorly located, then a posteromedialarthrotomy can be employed (Figure 6). An anteromedialor posteromedial approach can be successful for fragmentexcision and micro-fracture. However, if the fragmentrequires ORIF, then a medial malleolar osteotomy willnormally be required. However, this is a rare occurrence in

an acute lesion and more commonly utilized in chroniclesions. The management of chronic osteochondral fracturesis beyond the scope of this article but includes fragmentexcision and micro-fracture, retrograde trans-talar drilling,mosiacplasty, and juvenile cartilage cells (1, 3-8).

The presence of osteochondral damage to the talusduring ankle fractures is well known. Ferkel and colleagues

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Figure 4E. Inverted osteochondral fracture.

Figure 4G. Primary repair of the fibular collateral ligaments.

Figure 4F. A well-reduced osteochondral fracture fixated with anabsorbable screw.

Figure 4H. Mortise view of the reduction.

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Figure 5. Anteromedial approach for a medial talardome fracture with notch-plasty.

Figure 6A. Anterior-posterior radiograph demon-strating acute medial talar dome fracture fragments.

Figure 6B. Computed tomography scan.

Figure 6C. Posteromedial approach revealing fracture defect afterexcision.

reported that up to 80% of ankle fractures have chondral orosteochondral damage (9). The ankle joint can be evaluatedfor osteochondral damage either by arthrotomy when thefracture is being exposed or by using the arthroscopethrough traditional portals or the open incision. Treatmentmay be just documenting the damage because it isexcoriations/impactions of the articular surface. This may

aid in predicting long term outcome. If there are chondralor osteochondral fragments, they may be excised with orwithout micro-fracture (Figure 7). Large osteochondralfragments can undergo ORIF but this is a rare event. I havehad occasions where large chondral fragments have beenavulsed off the medial talar dome. These were reduced andfixated with absorbable pins if possible (Figure 8).

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Figure 8A. Radiograph of closed fracture dislocationof the ankle.

Figure 8B. Closed fracture dislocation. Figure 8C. Avulsion defect to the cartilage on the medial talardome.

Figure 7. Arthroscopic photograph of acute medial talar domedamage caused by an ankle fracture.

REFERENCES1. Shea MP, Manoli A. Osteochondral lesions of the talar dome. Foot

Ankle Int 1993;14:48-54.2. Kabbani YM, Mayer DP. Magnetic resonance imaging of the

osteochondral lesions of the talar dome. J Am Podiatric Med Assoc1994;84:192-5.

3. Berndt A, Harty M. Transchondral fractures (osteochondritisdissecans) of the talus. J Bone Joint Surg Am 1959;41:988-1020.

4. Canale ST, Belding R. Osteochondral lesions of the talus. J Bone JointSurg Am 1980;62:97-102.

5. Loomer R, Fisher C, Lloyd-Smith R, et al. Osteochondral lesions ofthe talus. Am J Sports Med 1993;21:13.

6. Flick AB, Gould N. Osteochondritis dessecans of the talus(transchondral fractures of the talus): review of the literature and a newsurgical approach for medial dome lesions. Foot Ankle 1983;5:165-85

7. Taranow WS, Bisignani GA, Towers JD, et al. Retrograde drilling ososteochondral lesions of the medial talar dome. Foot Ankle Int1999;20:474-80.

8. Hangody L, Kish G, Karpati Z, et al. Treatment of osteochondritisdissecans of the talus: use of the mosiacplasty technique–a preliminaryreport. Foot Ankle Int 1997;18:628-34.

9. Ferkel RD, Orwin JF.Ankle arthroscopy: a new tool for treating acuteand chronic ankle fractures. Arthroscopy 1993;9:456.

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Figure 8D. Fragment is recovered. Figure 8E. Fragment reduced and fixated with absorbableKirschner wires.

Figure 8F. Mortise view of open reduction internalfixation demonstrating an anatomic reduction.